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#1
06-04-2011, 04:56 PM
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how lean can I go
I have a lm1 wb and have gotten my cruise a/f to 16.5-17.3 cruising 55 mph There is some surging but am willing to put up with it for the much better gas milage.Am I hurting anything by running this lean?no load.
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76 T/A 455, cnc chamber E heads,OF hyd roller ,yella terra shaft rockers 11.47 119 |
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#2
06-04-2011, 05:16 PM
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Well use common sense, what do you think ? If it's surging than YES. These vehicles were not made for fuel economy. Period. I would make it run correctly and use it the way it was ment to be. From your sig. You did not build it for fuel economy you built it for racing. What did you expect....? JMHO..
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 My 1965 Lemans.... 
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#3
06-04-2011, 10:20 PM
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First, is probably not going to damage anything running it that lean at cruise unless the exhaust temps become excessively hot. However, running it to a point of surge is actually worse for gas mileage. Set the primaries just lean enough to eliminate any surging. Then start tuning your secondaries.
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"The Mustang's front end is problematic... get yourself a Firebird." - Red Forman |
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#4
06-04-2011, 10:40 PM
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Just got a call from a shop who pulled a freshly rebuilt Pontiac 400 with an extremely lean carb on it.
It ran fine for the first 2000 miles. The owner decided to take it on a 400 mile run at freeway speeds, and stuck 4 valves in the guides from excessive heat. Running extremely lean is not going to produce the best fuel encomony anyhow. The engine just sees too many variables where it needs more fuel to get the job done. If you lean one up till they loose power, surge, hesitate, flat on accelleration, down on power, etc, it's telling you it doesn't like those settings, and will run better and be more efficient giving it the fuel it wants/needs.....Cliff
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If you can read this, thank a teacher. If you can read this in English, thank a Veteran! https://cliffshighperformance.com/ 73 Ventura, SOLD 455, 3740lbs, 11.30's at 120mph, 1977 Pontiac Q-jet, HO intake, HEI, 10" converter, 3.42 gears, DOT's, 7.20's at 96mph and still WAY under the roll bar rule. Best ET to date 7.18 at 97MPH (1/8th mile), |
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#5
06-05-2011, 12:32 AM
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It blows me away all the posts I see on gas milage with a big old 400 or 455 or what ever! Gas milage is NOT what these cars are for.
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1969 GTO 4spd. Antique Gold/black, gold int. 1969 GTO RAIII 4spd. Verdoro Green/black, black int. 1969 GTO 4spd. Crystal Turquoise, black int. 1970 GTO 4spd VOE Pepper Green, green int. 1967 LeMans 428 Auto. Blue, black int. |
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